Outdoor heat exchanger and air conditioner

ABSTRACT

An outdoor heat exchanger has a total length of refrigerant flow passage in which a refrigerant flows along a refrigerant tube, and exchanges heat with outdoor air, the outdoor heat exchanger including a plurality of refrigerant tubes spaced apart from one another, a first and second header respectively coupled to both end portions of each of the refrigerant tubes, and a plurality of heat exchanging fins coupled to outer surfaces of the refrigerant tubes to widen a surface making contact with an outside, wherein a total length of a refrigerant flow passage in which a refrigerant flows along the refrigerant tube and exchanges heat with outdoor air is equal to or greater than about 1500 mm and equal to or less than about 6000 mm, in which range, the outdoor heat exchange achieves the optimum performance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the Korean Patent Application No. 10-2013-0064217, filed on Jun. 04, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

One or more embodiments relate to an outdoor heat exchanger and an air conditioner, and more particularly, to an outdoor heat exchanger and an air conditioner suggesting the optimal total length of a refrigerant flow passage.

2. Description of the Related Art

In general, an air conditioner is an apparatus configured to adjust temperature, humidity, air current, and distribution at suitable level for a human activity, and at the same time, to eliminate dust in air by use of a refrigeration cycle. As for the main components which compose the refrigeration cycle, a compressor, a condenser, an evaporator, an expansion valve, and a blower fan are provided.

A heat exchanger is an apparatus being used in the refrigeration cycle, and is configured to perform a role as a condenser or an evaporator. The heat exchanger includes a plurality of heat exchanging fins, and a refrigerant pipe coupled to the plurality of heat exchanging fins to guide a refrigerant.

With respect to the heat exchanger, various types of heat exchangers are present, including the heat exchanger having the form of a refrigerant pipe, and the heat exchanger having the form of a refrigerant tube. From the above, a heat exchanger having a micro-channel refrigerant tube is widely known to be superior in terms of heat transfer characteristic when compared to other forms of the heat exchangers. Thus, the heat exchanger having the micro-channel refrigerant tube is applied as the heat exchanger of a refrigerating apparatus.

However, in a case when the micro-channel refrigerant tube is applied as a heat exchanger of an air conditioner, unevenness in cooling/heating heat energy transfer performance may occur. Thus, applying the heat exchanger as such as a heat exchanger of an air conditioner provided with a dual purpose in freezing/heating is difficult. In addition, the performance of a heat exchanger may vary depending on the length of the micro-channel tube or the passage of a refrigerant.

SUMMARY

The foregoing described problems may be overcome and/or other aspects may be achieved by one or more embodiments of an outdoor heat exchanger designed in a way that the heat exchanger having a micro-channel tube is provided with high efficiency.

The foregoing described problems may be overcome and/or other aspects may be achieved by one or more embodiments of an air conditioner in which an outdoor heat exchanger is provided to have the optimal total length of a refrigerant flow passage and converted for use as an evaporator and a condenser.

Additional aspects and/or advantages of one or more embodiments will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of one or more embodiments of disclosure. One or more embodiments are inclusive of such additional aspects.

In accordance with one or more embodiments, an outdoor heat exchanger may include a plurality of refrigerant tubes, a first header, a second header, and a plurality of heat exchanging fins. The plurality of refrigerant tubs may be spaced apart from one another. The first header and a second header may be respectively coupled to both end portions of each of the plurality of refrigerant tubes. The plurality of heat exchanging fins may be coupled to outer surfaces of the plurality of refrigerant tubes to widen a surface making contact with an outside. A total length of a refrigerant flow passage in which a refrigerant flows along the refrigerant tubes and exchanges heat with outdoor air may be, for example, equal to or greater than about 1500 mm and equal to or less than about 6000 mm.

In a case when a heat transfer performance of the outdoor heat exchanger is equal to or less than about 4000 W, the total length of the refrigerant flow passage may be, for example, equal to or greater than about 1500 mm and equal to or less than about 5000 mm.

In a case when a heat transfer performance of the outdoor heat exchanger exceeds about 4000 W, the total length of the refrigerant flow passage may be, for example, equal to or greater than about 2500 mm and equal to or less than about 6000 mm.

The outdoor heat exchanger may further include a baffle provided at an inside of the first header and the second header to block a longitudinal flow of the refrigerant to change a direction of the refrigerant.

The baffle may be installed in plurality at an inside the first header and the second header.

The baffle may be installed in plural number lengthwise along the first header and the second header in an alternate manner.

The total length of the refrigerant flow passage may be an outcome of a length of the refrigerant tube multiplied by the number obtained by adding 1 to the number of the baffles.

The refrigerant tube may be, for example, a micro-channel tube having equal to or less than about 3 mm of hydraulic diameter.

The outdoor heat exchanger may be used by converting into a condenser and an evaporator.

The refrigerant may include, for example, at least one of R22 and R410a.

The refrigerant may include, for example, at least one of R32, R1234yf, and R1234ze.

In accordance with one or more embodiments, an air conditioner may include a compressor, an outdoor heat exchanger and an expansion valve. The compressor may be configured to compress refrigerant gas and discharge the compressed refrigerant gas. The outdoor heat exchanger may be configured to allow refrigerant to exchange heat with outdoor air. The expansion valve may be configured to expand condensed refrigerant liquid. The outdoor heat exchanger may include a plurality of refrigerant tubes disposed while being spaced apart from one another, and a plurality of headers coupled to both end portions of each of the plurality of refrigerant tubes. The total length of a refrigerant flow passage in which a refrigerant flows along the refrigerant tubes and exchanges heat with outdoor air may be, for example, equal to or greater than about 1500 mm and equal to or less than about 6000 mm.

The total length of the refrigerant flow passage may be an outcome of a length of the refrigerant tube multiplied by the number of paths in which refrigerant flows in one way.

The path may be formed by a first path in which the refrigerant flows in a first direction and a second flow path which is alternately formed with the first path and in which the refrigerant flows in a second direction opposite to the first flow path.

The air conditioner may further include a refrigerant conversion apparatus configured to change a flow of refrigerant. The outdoor heat exchanger may be installed to be converted into a condenser that condenses the refrigerant gas discharged from the compressor into refrigerant liquid to emit heat to an outside, and into an evaporator that evaporates the refrigerant liquid expanded in the expansion valve into refrigerant gas to absorb heat from an outside.

The refrigerant conversion apparatus may be positioned in between the compressor and the outdoor heat exchanger.

The refrigerant may include, for example, at least one of R22, R410a, R32, R1234yf, and R1234ze.

As is apparent from the above description, an outdoor heat exchanger may achieve the optimal performance within the above suggested range of the total length in which refrigerant flows along refrigerant tubes and exchanges heat with outdoor air.

In addition, an air conditioner, which is provided with an outdoor heat exchanger designed to perform at optimal level and configured to be converted for use as a condenser or an evaporator, may be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a drawing illustrating an outdoor heat exchanger in accordance with one or more embodiments.

FIG. 2 is a drawing illustrating a refrigerant tube and a heat exchanging fin of an outdoor heat exchanger in accordance with one or more embodiments.

FIG. 3 is a drawing illustrating a flow of refrigerant of an outdoor heat exchanger in accordance with one or more embodiments.

FIG. 4 is a drawing showing a relation between the unit performance of an outdoor heat exchanger and the total length of a refrigerant flow passage in accordance with one or more embodiments.

FIG. 5 is a drawing showing a relation between the performance of an outdoor heat exchanger and the total length of a refrigerant flow passage in accordance with one or more embodiments.

FIG. 6 is a drawing illustrating a refrigeration cycle of an air conditioner in accordance with one or more embodiments.

FIG. 7 is a drawing illustrating a heating cycle of an air conditioner in accordance with one or more embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to one or more embodiments, illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, embodiments of the present invention may be embodied in many different forms and should not be construed as being limited to embodiments set forth herein, as various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be understood to be included in the invention by those of ordinary skill in the art after embodiments discussed herein are understood. Accordingly, embodiments are merely described below, by referring to the figures, to explain aspects of the present invention.

FIG. 1 is a drawing illustrating an outdoor heat exchanger 1 in accordance with one or more embodiments, and FIG. 2 is a drawing illustrating a refrigerant tube and a heat exchanging fin of an outdoor heat exchanger in accordance with one or more embodiments.

An outdoor heat exchanger 1 may include a plurality of refrigerant tubes 20 through which refrigerant flows, a plurality of heat exchanging fins 30 coupled to outer surfaces of the plurality of refrigerant tubes 20, a first header 41 and a second header 42 respectively coupled to both end portions of each of the plurality of refrigerant tubes 20, and a baffle 50 configured to change the direction of a flow of refrigerant.

The refrigerant tube 20 may include a plurality of flow paths 21 provided at insides thereof with hollowness to allow liquid refrigerant to flow therethrough, and a partition 22 to divide the plurality of flow paths 21 from one another. The plurality of flow paths 21 may be disposed while being spaced apart from one another in a width direction of the refrigerant tube 20.

As the refrigerant tube 20, a micro-channel refrigerant tube may be used, for example. The micro-channel refrigerant tube 20 may be, for example, a tube having a hydraulic diameter of less than about 3 mm in general. The hydraulic diameter may be obtained by dividing the cross section of the tube by the circumference of the tube.

Refrigerant may emit heat to the surroundings or absorb heat from the surroundings through compression or expansion while flowing along the flow path 21 formed in the refrigerant tube 20. For the refrigerant to emit heat or absorb heat in an efficient manner through compression or expansion, the heat exchanging fin 30 may be coupled to the refrigerant tube 20.

The heat exchanging fin 30 may be disposed in plurality while being spaced apart from one another at equal intervals in a direction ‘C’ perpendicular to the direction in which the refrigerant tube 20 is extended. The heat exchanging fin 30 may be manufactured by using, for example, aluminum alloy or other material having high heat conductivity. The heat exchanging fin 30 may be attached to an outer surface of the refrigerant tube 20 to widen the heat exchanging area of outdoor air and the refrigerant tube 20.

As the interval in which the heat exchanging fins 30 are disposed is narrower, a greater number of the heat exchanging fins 30 may be disposed. However, in a case when the interval between the heat exchanging fins 30 is excessively narrow, the heat exchanging fin 30 may serve as a resistance against outdoor air that is being introduced toward the heat exchanger 1. Thus, since a concern over pressure drop is present, the interval between the heat exchanging fins 30 may be properly adjusted.

The heat exchanging fin 30 may include a plurality of insertion grooves 31 into which the plurality of refrigerant tubes 20 may be inserted, and a plurality of attaching plates 32 attached to the plurality of refrigerant tubes 20 in a state that the plurality of refrigerant tubes 20 may be inserted into the plurality of insertion grooves 31.

The insertion groove 31 may be provided in a form that corresponds to at least one portion of the heat exchanging fin 30, so that the at least one portion of the heat exchanging fin 30 may be inserted into the insertion groove 31. The insertion groove 31 may be formed between the plurality of attaching plates 32 that may be disposed while being spaced apart from one another in an extension direction of the heat exchanging fin 30.

The heat exchanging fin 30 may be provided in a form such that the refrigerant tube 20 may efficiently emit or absorb heat.

The first header 41 and the second header 42 may be coupled to both end portions of each of the plurality of refrigerant tubes 20, so that refrigerant may flow between the plurality of refrigerant tubes 20. The refrigerant tube 20 may be preferred to be formed as long as possible so as to widen the heat exchanging area of the refrigerant and outdoor air. However, a spatial limitation may limit the length of the refrigerant tube 20 in a single direction. Thus, the first header 41 and the second header 42 may be coupled to both end portions of the refrigerant tubes 20 to change the direction of the flow of refrigerant. At an inside the first header 41 and the second header 42, the baffle 50 may be provided to change the flow of refrigerant.

The baffle 50 may be provided to allow the flow of refrigerant entering along the refrigerant tube 20, which may extend in one direction, to flow in an opposite direction. The baffle 50 may be installed to prevent the refrigerant entering the inside the first header 41 and the second header 42 from flowing in upper and lower side directions.

The baffle 50 may be installed in plurality inside the first header 41 and the second header 42 while being spaced apart from one another. For the refrigerant to pass through the heat exchanger 1 along the refrigerant tube 20 while changing the direction of flow, the baffles 50 may be provided in an alternate manner at the first header 41 and the second header 42.

The outdoor heat exchanger 1 may include a first refrigerant pipe 43 and a second refrigerant pipe 44 connected to other refrigeration cycle components to pass refrigerant therethrough. The first refrigerant pipe 43 and the second refrigerant pipe 44 may be positioned at the first header 41 or the second header 42. As illustrated on FIG. 1, the first refrigerant pipe 43 and the second refrigerant pipe 44 may be located at an upper portion and a lower portion of the second header 42, respectively. One side of the first refrigerant pipe 43 may be connected to the upper portion of the second header 42, while the other side of the first refrigerant pipe 43 may be connected to an expansion apparatus. One side of the second refrigerant pipe 44 may be connected to the lower portion of the second header 42, while the other side of the second refrigerant pipe 44 may be connected to a compressor.

FIG. 3 is a drawing illustrating a flow of refrigerant of an outdoor heat exchanger 1 in accordance with one or more embodiments.

A first direction ‘A’ is referred as the direction heading from the second header 42 to the first header 41, and a second direction ‘B’ is referred to as the direction heading toward the first header 41 to the second header 42. The first direction ‘A’ and the second direction ‘B’ both are perpendicular to a direction ‘C’ in which the heat exchanging fin 30 is inserted into the refrigerant tube 20.

Refrigerant entering from the second refrigerant pipe 44 positioned at the lower portion of the second header 42 may be passed through the refrigerant tube 20 to flow in the first direction ‘A’. By a first baffle 50 a that may be positioned at the second header 42, the refrigerant, without flowing toward an upper portion of the second header 42, may flow along the refrigerant tube 20 to flow toward the first direction ‘A’. The refrigerant that is moved to the first header 41 that may be positioned at the end of the first direction ‘A’ may enter the first header 41 by pressure, and by a second baffle 50 b that may be positioned at an inside the first header 41, the refrigerant may flow toward the second direction ‘B’.

The refrigerant that is moved toward the second direction ‘B’ may be moved to the second header 42 again, and by the first baffle 50 a, the refrigerant may not move toward a lower portion of the second header 42. A third baffle 50 c that may be positioned above the first baffle 50 a inside the second header 42 may change the direction of the refrigerant again toward the first direction ‘A’. That is, inside the second header 42 having a lower portion closed by the first baffle 50 a and an upper portion closed by the third baffle 50 c, the refrigerant nay enter from the second direction ‘B’ and may exit toward the first direction ‘A’. The refrigerant moved toward the first direction ‘A’ may again enter the first header 41, and by the second baffle 50 b, the refrigerant may not flow downward. The refrigerant having the direction thereof changed by an end portion 41 a of the first header 41, which is closed, may flow toward the second direction ‘B’ to exit through the first refrigerant pipe 43.

The number of the baffles 50 positioned at the first header 41 and the second header 42 may be provided in a plural number and at various positions. However, for refrigerant to alternately move in the first direction ‘A’ and the second direction ‘B’, the baffles 50 may be alternately positioned at the first header 41 and the second header 42.

In addition, refrigerant may enter the first refrigerant pipe 43, flow in an opposite direction as described above, and exit through the second refrigerant pipe 44. That is, the outdoor heat exchanger 1 may be converted for use as a condenser and an evaporator. In a case when refrigerant enters the first refrigerant pipe 43 connected to a compressor 7 to exchange heat with outdoor air, and exits through the second refrigerant pipe 44 connected to an expansion valve 3, the heat exchanger 1 may be able to perform a role as a condenser. In a case when refrigerant enters the second refrigerant pipe 44 connected to the expansion valve 3 to exchange heat with outdoor air, and exits through the first refrigerant pipe 43 connected to the compressor 7, the heat exchanger 1 may be able to perform a role as an evaporator.

At this time, the total length passed by a certain refrigerant entering from one of the first refrigerant pipe 43 and the second refrigerant pipe 44 and exiting to the other one is referred to as the total length of refrigerant flow passage. That is, the total length of the refrigerant flow passage is defined as the total length in which a certain refrigerant exchanges heat with outdoor air.

The total length of the refrigerant flow passage as such may be related to a length 100 of a refrigerant tube connected in between the first header 41 and the second header 42 and the number of the baffles 50, as well as the number of paths passed by a refrigerant in one way. The length 100 of the refrigerant tube may be a length of one of the plurality of refrigerant tubes 20 that are spaced apart from one another. The length 100 of the refrigerant tube may be the value of the minimum distance that connects the first header 41 to the second header 42. The length 100 of the refrigerant tube 100 as such may be variable as an independent value.

The number of the baffles 50 and the number of the paths are the values that are dependent to each other, and thus, affect each other. In a case when the number of the baffles 50 is one, a refrigerant flows after changing the flow direction one time, and as a result, the number of the paths flowed in one way becomes two. On the contrary, in a case when the number of the paths having refrigerant flowing in one way is two, the direction of the flow of the refrigerant is needed to be changed one time, and thus, the number of the baffles 50 becomes one. Thus, the total length of the refrigerant flow passage may be expressed using the length of the refrigerant tube 20 and the number of the baffles 50, or may also be expressed using the length of the refrigerant tube 100 and the number of the paths.

The total length of the refrigerant flow passage may be obtained by multiplying the length 100 of the refrigerant tube 20 by the value obtained by adding ‘1’ to the number of the baffles 50. In addition, the total length of the refrigerant flow passage may be obtained by multiplying the length 100 of the refrigerant tube by the number of the paths. Since the total length of the refrigerant flow passage represents only the length in which the refrigerant exchanges heat, other than the length flowed by the refrigerant inside the first header 41 and the second header 42.

With respect to the outdoor heat exchanger 1 illustrated in FIG. 3, the total length of the refrigerant flow passage becomes the value obtained by multiplying the length 100 of the refrigerant tube by the value ‘4’, which is obtained by adding ‘1’ to ‘3’, the number of the baffles 50. In addition, the total length of the refrigerant flow passage becomes the value obtained by multiplying the length 100 of the refrigerant tube by ‘4’, the number of the paths in which refrigerant is moved in one way.

FIG. 4 is a drawing showing a relation between the unit performance of an outdoor heat exchanger and the total length of a refrigerant flow passage in accordance with one or more embodiments.

On the x-axis, the total length of the refrigerant flow passage in which refrigerant flows along the refrigerant tube 20 to exchange heat with outdoor air is expressed in millimeters at an interval of 1000 mm. On the y-axis, the value obtained by dividing the heat transfer performance of the outdoor heat exchanger by the heat transfer area is expressed in watts per square meter (W/m²) unit at an interval of 1000 W/m². For the convenience of the expression, the x-axis will show the values in the range of about 0 mm and 8000 mm, and the y-axis will show the values in the range of about 6000 W/m² and 16000 W/m².

A curve expressed on the x-y plane shows that the highest point is reached in the range when the x-axis value is equal to or greater than about 1500 mm and equal to or less than about 6000 mm. Thus, in the range when the total length of the refrigerant flow passage is equal to or greater than about 1500 mm and equal to or less than about 6000 mm, the unit heat transfer performance value may be provided with the highest value.

FIG. 5 is a drawing showing a relation between the performance of an outdoor heat exchanger and the total length of the refrigerant flow passage in accordance with one or more embodiments.

On FIG. 4, the line expressed on the x-y plane is shown in a way that the highest point at an upper portion of the x-y plane is toward the left side of the x-y plane, and at the lower portion of the x-y plane, the highest point is toward the right side of the x-y plane. The above may be distinguished by each performance level. On the table illustrated on FIG. 5, the heat transfer performance is shown in watt unit, and the total length of the refrigerant flow passage is shown in millimeter unit. In a case when the heat transfer performance of the outdoor heat exchanger 1 is equal to or less than about 4000 W, high efficiency may be obtained when the total length of the refrigerant flow passage is equal to or greater than about 1500 mm and equal to or less than above 5000 mm. In addition, in a case when the heat transfer performance of the outdoor heat exchanger 1 exceeds about 4000 W, high efficiency may be obtained when the total length of the refrigerant flow passage is equal to or greater than about 2500 mm and equal to or less than above 6000 mm.

FIG. 6 is a drawing illustrating a refrigeration cycle of an air conditioner in accordance with one or more embodiments, and FIG. 7 is a drawing illustrating a heating cycle of an air conditioner in accordance with one or more embodiments.

The refrigeration cycle that composes the air conditioner may include a compressor 7, a condenser, an expansion valve 3, and an evaporator. The refrigeration cycle may be configured to circulate a series of processes composed of compression-condensation-expansion-evaporation, and may be configured to supply low-temperature air after high-temperature air exchanges heat with low-temperature refrigerant.

The compressor 7 may discharge refrigerant gas after compressing the refrigerant gas in high-temperature/high-pressure state, and the discharged refrigerant gas may be introduced into the condenser. The condenser may condense the compressed refrigerant into a liquid state, and through the condensation process, heat may be discharged to the surroundings.

The expansion valve 3 may expand the liquefied refrigerant in a high-temperature/high-pressure state, which may be condensed at the condenser, into liquefied refrigerant in a low-pressure state. The evaporator may evaporate the refrigerant that is expanded by the expansion valve 3. The evaporator may achieve a freezing effect by the heat exchange with the subject that is to freeze, by use of the latent heat of the refrigerant, and may return the refrigerant gas in a low-temperature/low-pressure state to the compressor 7. Through such a cycle, the temperature of the indoor air may be adjusted.

An outdoor apparatus 200 a of the air conditioner may correspond to the compressor 7 and the outdoor heat exchanger 1 in the refrigeration cycle. The expansion valve 3 may be present at an indoor apparatus 200 b or at the outdoor apparatus 200 a, and an indoor heat exchanger 5 may be present in the indoor apparatus 200 b of the air conditioner.

When refrigerant is changed from a gas state into a liquid state, the heat exchanger may be used as the condenser, and when refrigerant is changed from a liquid state to a gas state, the heat exchanger may be used as the evaporator. The outdoor heat exchanger 1 and the indoor heat exchanger 5 may be used as the condenser or the evaporator. In a case when the outdoor heat exchanger 1 performs a role as the condenser, the indoor heat exchanger may be used as the evaporator, and in the case when the outdoor heat exchanger 1 performs a role as the evaporator, the indoor heat exchanger 5 may be used as the condenser.

FIG. 6 describes the refrigeration cycle when the outdoor heat exchanger 1 is used as the condenser and the indoor heat exchanger 5 is used as the evaporator to cool an indoor space. The liquefied refrigerant in a high-temperature/high-pressure state, which may be compressed at the compressor 7, may be introduced to the outdoor heat exchanger 1. The outdoor heat exchanger 1 may perform a role as the condenser to condense refrigerant gas into liquefied refrigerant to possibly discharge heat to outdoor air. The liquefied refrigerant exited from the outdoor heat exchanger 1 may be expanded at the expansion valve 3, and may be introduced to the indoor heat exchanger 5. The indoor heat exchanger 5 may evaporate liquefied refrigerant into refrigerant gas to take away heat from indoor air, so that the indoor may be cooled.

FIG. 7 describes the heating cycle when the outdoor heat exchanger 1 is used as the evaporator and the indoor heat exchanger 5 is used as the condenser to heat an indoor space. In contrast to the description provided in FIG. 6, refrigerant is moved in an opposite direction. The refrigerant gas that may be released from the compressor 7 by a refrigerant conversion apparatus 60 may be introduced to the indoor heat exchanger 5. The indoor heat exchanger may emit heat to indoor air, may condense refrigerant gas into liquefied refrigerant, and may send the liquefied refrigerant to the expansion valve 3. The refrigerant that may be passed through the expansion valve 3 may be phase-changed at the outdoor heat exchanger 1 into refrigerant gas to possibly take away heat from outdoor air.

Through the refrigerant conversion apparatus 60 as such, refrigerant may flow in a clockwise direction or in a counter-clockwise direction. As a result of the above, the air conditioner may become the air conditioner having a dual purpose in cooling/heating indoor air. The refrigerant conversion apparatus 60 may be positioned between the compressor 7 and the outdoor heat exchanger 1. The refrigerant conversion apparatus 60 may be installed adjacently to the compressor 7, which may be have the largest influence in the refrigeration cycle that composes the air conditioner, so that the direction of refrigerant may be changed.

As for the refrigerant, a plurality of refrigerants that may include, for example, R22, R410a, R32, R1234yf, and R1234ze may be used. Any refrigerant that includes at least one of R22 and R410a, which are commonly used in a conventional air conditioner, may be used, for example, but embodiments are not limited thereto. In addition, any refrigerant that includes at least one of low GMP (Low Global Warming Potential) refrigerants, such as R32, R1234yf, and R1234ze, which are recognized as alternative refrigerants, may be used, for example, but embodiments are not limited thereto.

While aspects of the present invention have been particularly shown and described with reference to differing embodiments thereof, it should be understood that these embodiments should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in the remaining embodiments. Suitable results may equally be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents.

Thus, although a few embodiments have been shown and described, with additional embodiments being equally available, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

What is claimed is:
 1. An outdoor heat exchanger, comprising: a plurality of refrigerant tubes; a first header and a second header coupled to each end portions of each of the plurality of refrigerant tubes, respectively; and a plurality of heat exchanging fins coupled to outer surfaces of the plurality of refrigerant tubes, wherein a total length of a refrigerant flow passage in which a refrigerant flows along the refrigerant tubes is equal to or greater than about 1500 mm and equal to or less than about 6000 mm.
 2. The outdoor heat exchanger of claim 1, wherein: when a heat transfer performance of the outdoor heat exchanger is equal to or less than about 4000 W, the total length of the refrigerant flow passage is equal to or greater than about 1500 mm and equal to or less than about 5000 mm.
 3. The outdoor heat exchanger of claim 1, wherein: when a heat transfer performance of the outdoor heat exchanger exceeds about 4000 W, the total length of the refrigerant flow passage is equal to or greater than about 2500 mm and equal to or less than about 6000 mm.
 4. The outdoor heat exchanger of claim 1, further comprising: a baffle provided inside the first header or the second header to block a longitudinal flow of the refrigerant to change a direction of the refrigerant.
 5. The outdoor heat exchanger of claim 4, wherein: the baffle on of a plurality of baffles installed inside the first header and the second header.
 6. The outdoor heat exchanger of claim 5, wherein: the plurality of baffles are installed in an alternate manner lengthwise along the first header and the second header.
 7. The outdoor heat exchanger of claim 6, wherein: the total length of the refrigerant flow passage is equal to a length of the refrigerant tube multiplied by the number obtained by adding 1 to the number of the baffles.
 8. The outdoor heat exchanger of claim 1, wherein: the refrigerant tube is a micro-channel tube having equal to or less than about 3 mm of hydraulic diameter.
 9. The outdoor heat exchanger of claim 1, wherein: the outdoor heat exchanger is used by converting the outdoor heat exchanger into one of a condenser and an evaporator.
 10. The outdoor heat exchanger of claim 1, wherein: the refrigerant comprises at least one of R22 and R410a.
 11. The outdoor heat exchanger of claim 1, wherein: the refrigerant comprises at least one of R32, R1234yf, and R1234ze.
 12. An air conditioner, comprising: a compressor configured to compress refrigerant gas and discharge the compressed refrigerant gas; an outdoor heat exchanger in which the refrigerant exchanges heat with outdoor air; and an expansion valve to expand condensed refrigerant liquid, wherein the outdoor heat exchanger comprises a plurality of refrigerant tubes and a plurality of headers coupled to each end portion of each of the plurality of refrigerant tubes, respectively, and a total length of a refrigerant flow passage in which a refrigerant flows along the refrigerant tube is equal to or greater than about 1500 mm and equal to or less than about 6000 mm.
 13. The air conditioner of claim 12, wherein: the total length of the refrigerant flow passage is equal to a length of the refrigerant tube multiplied by the number of paths in which refrigerant flows in one way.
 14. The air conditioner of claim 13, wherein: the path is formed by a first path in which the refrigerant flows in a first direction, and a second flow path which is alternately formed with the first path and in which the refrigerant flows in a second direction opposite to the first flow path.
 15. The air conditioner of claim 12, further comprising: a refrigerant conversion apparatus configured to change a flow of refrigerant, wherein the outdoor heat exchanger is installed to be converted into one of a condenser that condenses the refrigerant gas discharged from the compressor into refrigerant liquid to emit heat to an outside, and into an evaporator that evaporates the refrigerant liquid expanded in the expansion valve into refrigerant gas to absorb heat from an outside.
 16. The air conditioner of claim 15, wherein: the refrigerant conversion apparatus is positioned in between the compressor and the outdoor heat exchanger.
 17. The air conditioner of claim 12, wherein: the refrigerant comprises at least one of R22, R410a, R32, R1234yf, and R1234ze. 